The Montreal-based airline, which transports about 130,000 customers a day, said the union representing flight attendants made a recent counteroffer seeking “exorbitant” pay increases, and has rejected an offer to enter third-party binding arbitration.

Air Canada, Canada’s largest airline, says labor negotiations are “at an impasse” after tabling a sweetened offer to the union representing its 10,000 flight attendants.

Air Canada said on Tuesday it has asked the federal government for a referral to binding arbitration on its contract talks with the flight attendants union, after the airline declared an impasse in the negotiations.